1.000 atm of oxygen gas, placed in a container having a pinhole opening in its side, leaks from the container 2.14 times faster than does 1.000 atm of an unknown gas placed in this same apparatus. Which of the following species could be the unknown gas? A) Cl₂ B) SF₆ C) Kr D) UF₆ E) Xe

Question

Quizplus · Accepted Answer

Since oxygen gas is the reference point, the rate of effusion is directly proportional to the inverse of the square root of molar mass. Therefore, if a gas leaks 2.14 times slower than oxygen, it must have a molar mass greater than that of oxygen (32 g/mol). Only SF6 (146 g/mol) has a greater molar mass than oxygen. The other options have lower molar masses than oxygen and therefore cannot be the unknown gas.

1000 Atm of Oxygen Gas, Placed in a Container Having